Spa shell



FIG. 1 is a perspective view of a spa shell showing our new design;

FIG. 2 is another perspective view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a cross-sectional view thereof;

FIG. 5 is a cross-sectional view thereof;

FIG. 6 is a cross-sectional view thereof; and,

FIG. 7 is a cross-sectional view thereof.

The broken lines immediately adjacent the shaded areas represent the bounds of the claim, while all other broken lines are directed to environment and are for illustrative purposes only; the broken lines form no part of the claimed design. 

CLAIM The ornamental design for a spa shell, as shown and described. 